Numerous types of resonant structures, often used as electromagnetic filters, are known in the art. For most applications, a conductor and/or dielectric material must be held in a fixed position with respect to a wall such as a resonant cavity wall of a filter housing. In some applications, conductors are held between slabs of dielectric which are forced together using screws, springs or sometimes adhesive. In many applications, however, it is desirable that a resonator have little physical contact with other objects. Small screws or bolts may be placed through an opening in a resonator such as a dielectric puck, in order to attach the resonator to another structure with minimal physical contact. Although some degradation in performance of the resonator can undoubtedly be attributed to such mounting schemes, that degradation was generally small in comparison to other losses which affected the overall quality of the resonator.
The introduction of superconducting materials into resonant structures has significantly decreased the surface resistance of those structures, thereby raising the quality factor "Q" of the filtering devices made of the resonant structures. Losses due to mounting which were previously insignificant, have now become an important limiting factor in the quality of a filter. Prior methods, such as providing a threaded opening or the like in a resonator, are no longer desirable, since they interfere with the electromagnetic fields at the surface of the resonator. In general, the greater the size of a mounting mechanism or the more contact it has with the resonator, the more likely it is to interfere with the electromagnetic properties of the resonator or resonant cavity in which it is used. The desire for reduced size in mounting mechanisms is at odds with the need to hold the resonator at a precise location with minimal chance for mounting failure. In the case of filters using superconductors, the structural demands on the mounting mechanism are increased, since that mechanism will be subjected to temperatures ranging from room temperature to hundreds of degrees below 0.degree. C.